Jack-truck



J. F. MOELLER.

'JACK TRUCK.

APPLICATION manner. 29. 1919.

1,348,294. Patented Aug. 3,1920.

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Q \N g g g Ewe/2X07? Q 13 md 7- J. F. MUELLER.

JACK TRUCK.-

APPLICATION FILED OCT. 29. 1919.

Patented Aug. 3, 1920.

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.I. F. MUELLER.

JACK TRUCK.

APPLICATION FILED OCT. 29 1919'.

r, 5 MN MW W M r m v i h UNITED STATES PATENT OFFICE.

JOSEPH F. MUELLER, OF CHICAGO, ILLINOIS, ASSIGNOR TO MOELLER MACHINE- COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

JACK-TRUCK.

Specification of Letters Patent.

Patented Aug. 3, 1920.

Application men October 29, 1919. Serial No. 334,179.

This invention relates to a type of hand 7 operated truck for lifting and transporting heavy objects, commonly known as jack trucks; and more specifically the invention relates to that type ofjack trucks which embody a main frame mounted on wheels or.

casters, an upper load carrying frame connected to the main frame by parallel llIlkS, a pivoted handle which also serves, through intermediate mechanism, to elevate the upper frame and its load, and an oil check for easing the descending movement of the load carrying frame.

The principal object of the present invention is to provide an improved and simplified jack truck of the character specified, in which the load lifting operations may be easily performed through the intervention of a leverage multiplying transmission between handle and the load carrying frame. Another object is to providea construction of such a nature that the operation of raising the load will nothave any tendency to shift the front axle of the truck angularly. Another object is to provide an improved transmission gearing between the operating handle and the load carrying platform,.includ ing an improved dogging and foot operated release mechanism.

Still other objects and advantages of the invention will be apparent to those skilled in the art as the same becomes better understood by reference to the following descriptionv and the accompanying drawings, in which- Fi'gure 1 is a top plan view, partly broken away and in section;

Fig. 2 is a side elevation partly broken away and in section; I V

Fig. 3 is a front elevation, partly broken away and in section;

'Fig.,4is an enlarged side elevation of the.

front portion of the truck, partly broken out and in section, and showing the handle lever in full lines in raised position, and in dotted lines in lowered position; and V Fig. 5 is a detailed side elevation of the ratchet wheel.

the

Referring to the drawings, the main frame of the truck consists of a pair of parallel side bars 10, rear connecting and spacing rod or bar 11, and a front yoke-like connecting and spacing bar 12,in which latter is vertically swiveled by means of king pin 13 (Fig. 3) the forward bolster 14 carrying a front axle 15 on which are journaled the front wheels 16. In andbetween the side bars 11 is journaled the rear axle 17 carrying the rear wheels 18. I

On the bolster 14 are a pair of spaced lugs 19 (Fig. 3) in which is mounted the pivot pin 20 of" a forwardly extending handle lever 21.

The upper or load carrying frame com-, prises apair of parallel side bars 22 and cross connecting or spacing bars 23, 24 and 25. The connecting bars 24 and 25 of the upper frame are jointed to the lower frame by a forward pair of links 26 connecting the cross bar 24 of the upper frame to an intermediate cross bar- 27 of the lower frame, and by a similar pair of rear links 28 connecting the cross bar'25 of theupper frame to the check. The purpose ,of this device is to I cushion the lowering movement of the upper frame when under load, and since these" de vices are quite commonly employed in jack trucks of this type and no novelty broadly is claimed therefor, detailed description thereof is not necessary. I have, however, incorporated in the present device an improved structural feature consisting of a link 30 which connects the cross bars 23 and 24 of the upper frame in a plane coincident with the vertical plane of the axis of the oil-check 29, the purpose of this being to distribute the strain between thetwo cross-bars or rods 24 and 23, thereby preventing any deflection of the cross-bar 24 which might impair the proper functioning of the forward links 26. This link 30 also distributes to the cross-bar 24 a portion of the lifting strain imposed on the front cross bar 23 by the lifting mechanism hereinafter described.

Referring now to the mechanism for lifting the load carrying frame, holding it in elevated position, and releasing it when desired, integral with the front yoke 12 of the marrying frame of the truck.

main frame is a pair of parallel upstanding brackets 31 (Fig. 3) in which are journaled a lower shaft and an upper shaft 33. Fast on the shaft 32 is a spur-pinion 34 which meshes with a spur-gear 35 fast on the upper shaft 33. Keyed on the ends of the shaft 33 are a pair of arms 36, the lower ends of which are connected by links 37 to the forward cross bar 23 of the upper frame. Also fast on the shaft 32 and located in the vertical plane of the pivot pin 13 of the front axle is a combined lifting and dogging ratchet comprising a central lifting ratchet disk 38 anda pair of dogging ratchet disks 39 on either side thereof. The lifting ratchet 38 is formed with a series of radial teeth 38 (Fig. 5), and each of the dogging disks 39 is formed with a series of radially pro jecting rounded'teeth 39, which latter coopreate with the hook-shaped ends 40 (Fig.

4) of a pair of twin lifting pawls 40 that are pivotally connected at their other ends by a pin 41 to the handle lever 21, and are rigidly spaced by an intermediate block 42. By referring to Fig. 1 it will be observed that the With the central ratchet disk 38 cooperates a dog 43, best shown in Fig. 4, that is pivoted at 44 on a lug 45 carried by the yoke 12, this dog being pressed towardthe periphery of the ratchet disk by a spring 46, and automatically snapping into engagement with the teeth 38' of the ratchet disk as the latter.

is turned in a direction to raise. the load This dog is adapted to be disengaged from the ratchet by a foot lever 47, pivoted at 48 to one of the vertical brackets 31 of the yoke 12 and having a depending arm 47 that bears against the dog 43 in a manner clearly shown in Fig. 4. t

In the operation of the device, the truck, with the upper frame in its lowermost position, in which it rests upon the lower frame, is backed beneath an object to be lifted and transported, and by swinging the handle lever 21 in a vertical plane, the load is raised through the pawl and ratchet and spur-gear elevating means in a manner readily apparent. Heavy loads are very easily raised by the'multiplication of the leverage of the handle lever securedthrough the pinion and gear transmission 34, 35. At each up stroke of the handle lever the load is sustained by the dogging pawl 43, and when the load is to be lowered, the operator merely steps on the releasing lever 47, and the upper frame drops under the gravity of the load, cushioned by the oil-check 29. It will be observed that both the fulcrum 20 of the handle lever and the load-resistance point 41 lie in the vertical plane of the swivel-pin 13 of the forward axle, so that during the raising of the load there is no tendency to cant or swing the forward axle of the truck.

I claim 1. In a jack truck, the combination of a main frame mounted on wheels, an upper frame, parallel links connecting said main and upper frames, a handle lever pivotally connected to said main frame, a lifting pawl pivoted to said handle lever, a ratchet journaled on said main frame and cooperating with said lifting pawl, a pinion fast with said ratchet, a gear'wheel actuated by said pinion, and connections from said gear wheel to said upper frame.

2. In a jack truck, the combination of a main frame, a pair of rear wheels'therefor, a bolster vertlcally swiveled on said main frame, a front axle carried by said bolster, wheels on said front axle, an upper frame, parallel links connecting said main and upper frames, a handle lever pivoted to said bolster, a lifting pawl pivoted to said handle lever, a ratchet journaled on said main frame and cooperating with said lifting pawl, a pinion fast with said ratchet, a gear wheel actuated by said pinion, and power transmitting connections from said gear.

wheel to said upper frame.

'3. In a jack truck, the combination of a main frame, a pair of rear wheels therefor, a bolster vertically swiveled on said main wheels on said front axle, an upper frame,

parallel links connecting said main and up-l per frames, a handle lever pivoted to said bolster in the vertical plane of the swivelaxis of said bolster, a lifting pawl pivoted to said handle lever, a ratchet journaled 011 said main frame in the vertical plane of said swivel-axis and cooperating with said lift-. ing pawl, and power transmitting connections from said ratchet to said upper frame.

4. In a jack truck, the combination} of a main frame mounted on wheels, an upper frame, parallel links connecting said main and upper frames, a handle lever pivotally connected to said main frame, a lifting pawl pivoted to said handle lever, a pairof bearing brackets extending upwardly from the forward portion of said main frame, a pair of shafts mounted in said brackets, a ratchet wheel on one of said shafts cooperating with said lifting pawl, a pinion rigid with said ratchet wheel, a gear wheel on the other of said shafts and meshing with said pinion, crank arms on said last named shaft, and links connecting said crank arms to said upper frame.

5. In a jack truck, the combination of a main frame mounted on wheels, an upper frame, parallel links connecting said main 10!), frame, a front axle carried by said bolster,

. fastwith said ratchet wheel, a spring pressed dog cooperating with said detent ratchet, and a foot lever for releasing said (I. In a jack truck, the combination of a main frame and front and rear axles carry-- ing supporting wheels therefor, an upper frame having a pair of longitudinally spaced cross-connecting bars adjacent to its forward end, parallel links connecting said main and upper frames, an oil check connected at its rear end to said rear axleand at its forward end to the rearmost of said cross-connecting bars, and a link connecting said cross-connecting bars in line with the axis of said oil check.

7. In a jack truck, the combination of a main frame mounted on wheels, an upper frame having a pair of longitudinally spaced cross-connecting bars adjacent to its forward end, parallel links connecting said main and upper frames, a handle lever pivoted to said main frame, power transmitting connections from saidhandle lever to said upper frame including a pair of links connected to the foremost of said cross-connecting bars, and a link centrally connecting said cross-connecting bars whereby the pull of said pair of links is'partiallyv transmitted from the foremost to the rearinost of said cross-connecting bars.

8.'In a ack truck, the combination of a main frame mounted on wheels, an upper frame, parallel links connecting said main and upper frames, a handle lever pivoted to said main frame, a ratchet wheel journaled on said main frame, power transmitting connections from said ratchet wheel to said upper frame, a pawl pivoted to said handle lever and having a hook-shaped free end cooperating with the teeth of said ratchet wheel to turn the latter when said handle lever is lowered, and detent mechanism associated with said ratchet wheel.

9. In a jack truck, the combination of a 7 main frame mounted on wheels, an upper frame, parallel links connecting said main and upper frames, a handle lever pivoted to said main frame, twin'ratchet wheels jour-' naled on said main frame, a detent ratchet between and rigid with said twin ratchet Wheels, power transmitting connections from said ratchet wheels to said upper frame, a pawl pivoted to said handle lever and having a bifurcated hook-shaped free end cooperating with the teeth of said ratchet wheels to turn the latter when said handle lever is lowered, and a spring actuated dog associated with said intermediate detent ratchet. v

10. In a jack truck, the combination of a main frame mounted on wheels, an upper frame, parallel links connecting said main and upper frames, a handle lever pivoted to said main frame, a ratchet wheel mounted on said main frame, power transmitting connections from said ratchet wheel to said upper frame, and a pawl cooperating with said ratchet wheel to effect the raising of said upper frame, said pawl having a bifurcated lower endpivoted to said handle lever JOSEPH F. MOELLER. 

